1. Field of the Invention
The present invention relates to a working fluid which comprises plural halogenated hydrocarbons and is used in refrigerators, heat pumps and the like.
2. Description of the Related Art
Hitherto, as working fluids in refrigerators, heat pumps and the like, are used halogenated hydrocarbons derived from methane or ethane, which are also called as fluorinated halocarbons. They work at such utilization temperature that a condensation temperature and/or an evaporation temperature are from about 0 (zero) to about 50.degree. C. Among them, dichlorodifluoromethane (CCl.sub.2 F.sub.2, R12) with a boiling point of -29.8.degree. C. is widely used as a working fluid in a refrigerator, an air conditioner for an automobile and a large size refrigeration system.
Recently, depletion of the ozone layer in the stratosphere with the fluorinated halocarbon is seriously discussed as one of global environmental problems, and amounts to be used and produced of some fully halogenated chlorofluorocarbons (CFCs) which have high ozone depletion potential are limited by the Montreal Protocol. In future, their use and production will be banned.
R12 has an ozone depletion potential (hereinafter referred to as "ODP") of 1.0 when ODP of trichlorofluoromethane (CCl.sub.3 F, R11) is defined to be 1 (one). The reduction of the use and production amount of R12 will have serious influence on human life since the refrigerators and the air conditioners are widely used. Therefore, it is highly desired to quickly develop a working fluid which has a small ODP and can be used as a substitute for R12.